Hate to break it to you, but rental income is typically subject to BIRT and NPT, not SIT.
Out-of-city/state rental income from an LLC.
Calculating it out PA+Philly taxes on this would be 6.99%. That's not too out of line with other states with higher income taxes especially combined with local income taxes (which would often cover dividends, gains, etc.)
My two biggest worries were:
1) Being taxed twice on it. Paying Philly tax and that higher out-of-state tax. That pushes up the number from 6.99% to over 10% if I'm paying full other state and local taxes and Philly taxes. (Reciprocity would wipe out any PA liability).
2) Filing Philadelphia taxes. The other state where I've had to deal with local taxes, they were just an add on percentage to your state return so there was no confusion about what to include. In Philly, half the people don't file, there's little enforcement, and the regulations aren't clear to me on some of the issues.